This study showed that the use of NIR-ICG tended to associate with the lower incidence of CD grade ≥ III complications (p = 0.076). No CD grade ≥ II intestinal complications were observed in the NIR-ICG group. When limited to the group that underwent intestinal resection, the use of NIR-ICG significantly associated with the lower incidence of postoperative complications (p = 0.009).
Paralytic ileus was common in the non-NIR-ICG group. It is possible that a failure to identify poor vascular perfusion through subjective evaluation in this group resulted in slowing of intestinal peristalsis and paralytic ileus. In the intestinal resection group, four cases of SSIs with CD grade ≥ II were observed. All patients were in the non-NIR-ICG group. By evaluating vascular perfusion with NIR-ICG, it may be possible to avoid unnecessary intestinal resection and reduce the risk of SSI due to contamination.
AL is one of the most serious complications after intestinal resection for HVI, with a reported incidence of 2.5 %–6.6% of all colonic injuries [6, 7]. In addition, emergency resection is an independent risk factor for AL (relative risk 4–6, 95% confidence interval 1.9–9.8). The presence of peritonitis is also a predictor of AL [16]. Since trauma patients who require emergency surgery are presumed to be at high risk for AL, preventive measures should be implemented. Previous studies have reported that vascular perfusion is important for reducing AL [8, 9]. Compared to the less reliable subjective assessments [12], objective confirmation of good vascular perfusion in the resected bowel stump by NIR-ICG may help prevent complications due to impaired vascular perfusion. Considering the incidence of AL reported so far, further studies are needed to evaluate the efficacy of NIR-ICG for HVI.
AL increases mortality, length of hospital stay, 30-day readmission, and postoperative infection rates [16, 17, 18, 19]. As a result, hospital costs increased by more than $25,000 in the United States [19] and more than €50,000 in Europe [20] when compared to low-cost ICG. Complications, not limited to AL, doubled the length of hospital stay, increased the average total cost by $25,000, and decreases total balance and turns negative, resulting in a large loss [21]. In addition, treatment of SBS requires long-term infusions, leading to an increased risk of infection and increased cost and mortality [22]. The same is true for SSI, which has disadvantages such as prolonged hospital stay, increased costs, and prolonged use of antimicrobials [23]. We believe that the use of NIR-ICG will reduce the risk of these complications and their associated consequences.
A few studies have also investigated the use of NIR-ICG for brain injuries and burns. However, there are no reports of its use in torso trauma and to the best of our knowledge, this is the first report using NIR-ICG for intestinal and mesenteric injury. The use of NIR-ICG has made it possible to objectively evaluate intestinal vascular perfusion, which was previously evaluated using subjective evaluation of mucosal color, mesenteric vascular pulsation, and intestinal peristalsis [8]. An objective evaluation of intestinal vascular perfusion can ensure sufficient perfusion at the intestinal anastomosis and avoid unnecessary intestinal resection, which may reduce the incidence of complications caused by intestinal and mesenteric injuries, such as AL and SSI. In addition to improving patient outcomes, this could shorten hospital stays, reduce costs, and optimize the use of antimicrobials.
NIR-ICG has several advantages including the ability to perform rapid evaluation of vascular perfusion within 60 seconds in real-time using a simple technique, and the ability to record images allowing for retrospective evaluation.
Achieving hemostasis is the mainstay of treatment in hemodynamically unstable patients. NIR-ICG should be performed in patients with stable disease. The results of this study demonstrate the feasibility of NIR-ICG in patients with intestinal and mesenteric injury with stable hemodynamics after emergency surgery.
This study has several limitations worth noting. First, this was a retrospective, single-center study; as this was not a randomized controlled trial, the selection bias could not be ruled out and we could not confirm the effectiveness of NIR-ICG. Second, the number of included patients was small and further studies with a large study population warranted to validate our results. In this study, the NIR-ICG group included only males, and so randomization for gender differences is also needed. Third, factors other than vascular perfusion might be the cause of intestinal complications such as AL. Future studies should consider the association of other traumatic sites, operator factors, and preoperative nutritional status on the risk of intestinal complications. Fourth, a difference in the proportion of complications among subgroups was significant but underpowered, due to a limited sample size. Finally, due to the diverse background of trauma, the protocol for using NIR-ICG has not been determined. Therefore, multi-institutional randomized studies are needed to confirm whether NIR-ICG can reduce complications such as the AL rate in intestinal mesenteric injury.